Still better than a finished 29-year old Coutinho and 30-year old Griezmann. Dembele will still be only 27 when his new contract runs out. And if isn't injured for more than one season in these next four years, he will still have value and a number of clubs out there willing to take a chance on him for 30-40M, if we decide to sell him. Still better than letting him go for free and watching him possibly explode elsewhere. And even if he doesn't ever come good, there's no use in letting him go for free, cause even with limited playing time he can still be an asset to us, especially now, when Messi is gone and our attack will actually be fluent and looking to pass the ball to the best positioned player. If we adopt a more counter attacking approach sometimes (i'm guessing Koeman will go that way against stronger teams), he'll fit in even more.
How high are you???